Parity-anomalous Hall response of chiral Lifshitz fermions
Phys. Rev. B 114, 245417 – Published 20 October, 2026
DOI: https://doi.org/10.1103/dttl-27rf
Abstract
The parity anomaly of a single massless Dirac fermion is manifested as a half-quantized Hall response once the required parity-breaking regularization is supplied. We study the corresponding response for two-dimensional chiral Lifshitz fermions. For a node with low-energy coupling , the Fermi-loop winding number gives an anomalous Hall response . We examine this mechanism in chiral multilayer Haldane models tuned to a valley-selective critical line, where a single gapless chiral Lifshitz fermion remains at the valley. For the AB, ABC, and ABCA stacks, the projected pseudospin textures give , while Kubo calculations yield ; integrated equilibrium boundary currents reproduce the same sequence. Six-terminal simulations with dephasing further show that the Hall conductivity is quantized at while the longitudinal conductivity remains finite. These results identify gapless chiral Lifshitz fermions as a higher-order, winding-controlled generalization of the parity-anomalous Hall response, distinct from a quantum anomalous Hall insulating state even when is an integer.